This is often confused with a composite key whereby even though this is also a key that consists of 2 or more attributes that uniquely identify an entity occurrence, at least one attribute that makes up the composite key is not a simple key in its own right.
No restriction is applied to the attributes regarding their (initial) ownership within the data model. This means that any one, none, or all, of the multiple attributes within the compound key can be foreign keys. Indeed, a foreign key may itself be a compound key.
Publication No. WO/2009/143712 Published on Dec. 3, Assigned to Beijing E-Henxen Authentication Technologies for Compound Public Key Generation Method (Chinese Inventors)
Dec 04, 2009; GENEVA, Dec. 4 -- Xianghao Nan and Huaping Chen, both of China, have developed a compound public key generating method. The...